Audio monitoring can't currently be panned, though that's a great idea.
The way monitoring is done will soon (well relatively soon) be completely revamped using the new concept of "buses". The plan is to be able to make routes between the output of a track and several destinations: audio ports (what we have now), other tracks (so you can do bounce recording), and buses. A bus would be similar to a DAW, you can use them to merge inputs from several tracks, modify that with levels, panning, and effect inserts, and then route that somewhere else.